Metabolic prevention, Johannesburg
Prediabetes: act before it becomes diabetes.
Prediabetes is a chance to change course. Assessment identifies why your glucose is drifting up and what will most effectively bring the risk down.
In short
Prediabetes describes glucose levels above the normal range but below the diagnostic threshold for diabetes. In non-pregnant adults, ADA 2026 criteria include HbA1c 5.7–6.4%, fasting plasma glucose 5.6–6.9 mmol/L, or a 2-hour glucose of 7.8–11.0 mmol/L during a 75 g oral glucose tolerance test. It is a risk state rather than an inevitable progression to diabetes, and treatment focuses on weight where relevant, physical activity, nutrition, sleep, cardiovascular risk factors and medication in selected high-risk patients.
Medically reviewed by Dr Arnav Kapur, MBBCh Cum Laude
The approach
Understand first. Then treat.
Prediabetes often sits alongside visceral adiposity, hypertension, raised triglycerides, fatty liver and other features of metabolic dysfunction. That makes it useful as a warning sign for more than diabetes alone.
The most valuable response is not simply to repeat HbA1c every few months. It is to understand why risk is elevated, identify the modifiable drivers and make a plan that reduces both diabetes and cardiovascular risk.
What we assess
- HbA1c
- Fasting plasma glucose
- 75 g oral glucose tolerance testing where it adds information
- Weight, waist and body composition
- Blood pressure
- Lipids and broader cardiovascular risk
- Family history and previous gestational diabetes
- Sleep and obstructive sleep-apnoea risk
- Medication associated with dysglycaemia
- Liver health and metabolic dysfunction where relevant
How prediabetes is diagnosed
Prediabetes is diagnosed using established glucose criteria rather than fasting insulin alone. HbA1c, fasting plasma glucose and the 2-hour value during a 75 g oral glucose tolerance test identify overlapping but not identical groups, so the most appropriate test depends on the clinical context.
Prediabetes is a cardiovascular warning sign too
People with prediabetes often have other cardiometabolic risk factors such as visceral adiposity, hypertension, high triglycerides or low HDL cholesterol. Assessment therefore includes blood pressure, lipids, smoking and other cardiovascular risk rather than focusing only on future diabetes.
Lifestyle intervention genuinely changes risk
Weight reduction where appropriate, regular physical activity, resistance training and sustainable dietary change can materially reduce progression to type 2 diabetes. The plan should fit the person rather than rely on a generic 'diabetic diet'. Sleep, alcohol and medication are addressed where they contribute.
When medication is considered
Medication is not automatic for every person with prediabetes. In selected higher-risk patients, including some with significant obesity, previous gestational diabetes or worsening dysglycaemia despite lifestyle intervention, pharmacological prevention or medical weight management may be appropriate after individual assessment.
Common questions
Answers before you book.
Is prediabetes reversible?
Glucose values can return to the normal range, particularly with weight loss where relevant, improved activity and better metabolic health. That does not erase future risk completely, so ongoing prevention still matters.
Can I have prediabetes if my fasting glucose is normal?
Yes. HbA1c or the 2-hour glucose during an oral glucose tolerance test can be abnormal even when fasting glucose is normal because the tests measure different aspects of glucose regulation.
Is fasting insulin used to diagnose prediabetes?
No. Prediabetes is diagnosed using HbA1c, fasting plasma glucose or an oral glucose tolerance test. Fasting insulin can provide additional context in selected metabolic assessments but is not a standard diagnostic criterion.
How often should prediabetes be checked?
ADA guidance recommends at least yearly testing for people with prediabetes, with timing adjusted according to risk, trajectory and treatment changes.
This page provides general health information and does not replace individual diagnosis or treatment. Diabetes and prediabetes should be diagnosed using validated glucose criteria.
Ready to start properly?
- Insulin Resistance
- Type 2 Diabetes Care
- Visceral Fat
- Metabolic Health & Diabetes
- Medical Weight Management
- Cardiovascular Risk Assessment
- Longevity & Preventative Medicine
Centre of Advanced Medicine, 13 Scott St, Waverley, Johannesburg
Monday to Friday, 07:40 to 17:00
011 440 8721